Of the various dispenser types available for dispensing various spreadable products (including fluids, suspensions, lotions, creams, emulsions, and gels) and applying them to a surface, one widely used type of dispenser is a roll-on type of applicator. In this type of dispenser, a rotating element (often spherical or cylindrical) is in fluid communication with a product reservoir within the package. When the rotating element is drawn across the desired surface, a film of product having a predetermined thickness is drawn out of the dispenser on the surface of the rotating element. The thickness of this film is controlled by a number of factors, including the clearance between the element surface and the element-capturing portion of the package and the viscosity of the product. As the rotating element rolls over the surface, the film of product is applied to the surface along the contact path of the element.
Current commercially available roll-on packages utilize the rotating element to not only apply the product to the desired area, but also to perform the metering/dispensing function. If a consumer utilizes the element to further distribute product already applied, additional product continues to be dispensed as the element rotates within its socket. This tends to result in uneven, generally wet and messy applications with wasted product.
Current commercially available packages also tend to have a comparatively large percentage of the rotating element's surface area exposed outside of the package, often on the order of 40-45%. The actual contact area of the element in conjunction with most surfaces is much less, on the order of 20-25%. Thus, while a comparatively large element is utilized to reduce the curvature of the contact surface, the remaining exposed surface is carrying forth a film of the product which cannot be applied to a corresponding surface and hence must either follow the element back inside the container or else build up a thicker film on this non-contacting exposed surface which is oriented 90.degree. to the direction of travel of the rotating element. This thicker film, as well as excess product sheared from the surface of the element by the fitment, tends to form ridges of heavy product application at either side of the path the element travels across the desired surface. The sheared-off excess product may even ooze over the edge of the fitment holding the element. The large rotating surface also tends to attract threadlike elements such as loose threads, fuzz, or hair which may be present on the desired surface, and to draw them into the clearance space between the rotating element and the fitment.
Accordingly, it would be desirable to provide a roll-on type product dispenser which is easy to use and provides for a more even, less messy application of the product. It would also be desirable to provide a roll-on type dispenser which exhibits a reduced tendency to attract and capture loose threadlike elements which may be present on the desired surface for application.